I didn't mention C63 above and when i say M3 is better than Carrera S i mean 2 years ago when the M3 6 speed was first came out it was able to beat Carrera S in every performance category. And C63 can only beat M3 in a straightline but in low RPM tractability in high gears, handling, build quality and even comfort M3 will beat it easily.
I just find some of the sweeping statements to be unfair. I don't know how the M3 will "beat" a C63 in "build quality", in fact, I'd beg to differ. I'm more confident in the constructional quality in the C63, and if I had to put lots of miles on either, I'd probably feel more confident in the C63 as well. I wouldn't make a statement that I think it's "better", because I don't really know, but I do know which one I feel I'd give the nod to. If you're speaking of interior refinement, then sure, I'd agree with you, as the W204's interior is pathetic and crude (yet still build to an extremely high degree of solidity and fit/finish), and frankly, an embarrassment for M-B.
The power delivery maybe similar but obviously what American V8s lack is the superb refinement of Mercedes V8s.
M-B makes perhaps the best V8's around, no argument there. But I wouldn't say a good American V8 lacks the refinement necessarily. The Americans have made some of the best V8's of all time, and many of them are plenty refined, even ones that have a double-character, like the Mustang (intended to be hard and muscle-y, yet livable). Even GM with their dinosaur OHV V8's are masterfully engineered, they're using an ancient approach, yet have motors that provide insane HP, insane MPG, insanely good reliability/longetivity/durability, and are smooth as silk.
Also, it seems a lot of people here aren't giving the Mustang credit where it's due. Maybe it's not as engaging as an M3 (hilarious to even have to seriously say that, as in there's a serious argument about it), however, don't write it off as any old "straight line only/clumsy" Mustang. Everyone who *has driven* the car, seems to feel it is shockingly outperforming cars one would never assume it to, and this is with the live axle, etc. Wait 'till the next Mustang comes out....